package Homework1;

import java.util.Scanner;

public class Homework1_1 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        double r, h, V;
        r = input.nextDouble();
        h = input.nextDouble();
        V = Math.PI * r * r * h;
        System.out.println(V);
    }
}
